This invention relates to an eyeglass assembly which comprises a lens and a frame member, and to a method of assembling an eyeglass.
An eyeglass will comprise frame components and lens components. It will generally include two lenses (although it might include just one). An eyeglass which includes two lenses will generally include, as frame components, a nose bridge by which the two lenses are connected to one another, and temples which extend from the lenses to fit against the user's ears. The present invention is concerned with fastening frame components and lens components together.
It is known from U.S. Pat. No. 6,164,775 to fasten frame components to the lens of an eyeglass using lugs which are formed on the edge of the lens. The frame components are formed with a gripping portion which includes a pair of gripping arms. The configuration of the gripping portion can change between an open configuration in which the arms are spaced apart, and a closed configuration in which the arms grip the lug. The gripping portion can be formed from a shape memory alloy. Articles formed from shape memory alloys can exhibit shape memory properties associated with transformations between martensite and austenite phases of the alloys. These properties include thermally induced changes in configuration in which an article is first deformed from a heat-stable configuration to a heat-unstable configuration while the alloy is in its martensite phase. Subsequent exposure to increased temperature results in a change in configuration from the heat-unstable configuration towards the original heat-stable configuration as the alloy reverts from its martensite phase to its austenite phase. The transformation from austenite to martensite on cooling begins at a temperature known as the Ms temperature, and is completed at a temperature known as the Mf temperature. The transformation of martensite to austenite upon heating begins at a temperature known as the As temperature and is complete at or above a temperature known as the Af temperature. Shape memory alloys are discussed in an article by L McDonald Schetky in the Encyclopedia of Chemical Technology (edited by Kirk-Othmer), volume 20 pages 726 to 736.